Thanks for your attention, gents.  I've changed the selector to a.CrossChildPageLIstLIne:link (and :visited, :hover, :active) and am seeing *some* control over the CSS now.  However, I am unable to use a reverse indent with any effect.  I am using: 

          text-indent:-50px;
          padding-left:20px;

But it is as if the text-indent portion is not working in the two browsers I use for testing (IE8 and Firefox).  Firebug shows that the browser is receivng the text-indent, but it has no effect.

This worked great until the upgrade.

To your questions:
1. Important attributes: no text decoration, reverse indent
2. The site was upgraded by my host (PowerDNN). They're normally pretty good about not touching stuff.  Having said that, the default.css has the date of the upgrade and is smaller in size than the default.css file from before the upgrade.  Should I restore an old version of the default.css?

1) You would have better, more reliable results from using margins on the whole list.
2) That sounds about right.  I would not restore the old version as you will just have this problem on the next upgrade. Better to do as you have and amend the skin files.